The Mount Vernon Community School District is asking parents and others to turn off their vehicles so students won’t have to breathe so much pollution from engine exhaust.

Cedar Rapids television station KCRG says (http://bit.ly/1cAXysz) the district wants drivers to observe a 10-second rule: Don’t leave vehicles running longer than 10 seconds while waiting.

The district’s transportation department head mechanic is Jeff Merritt, and he’s been working with the Linn County Public Health Department on the initiative. Merritt says he’s posted signs at the schools and in district buses.